If your Keep falls, you will lose the battle and your resources. Ensure you base layout focuses your defense on the Keep. Moats cannot be taken down or passed. Place them logically to funnel your enemy to areas where they can be taken down easier. Note that their long ranged units can shoot over moats. Build your Keep in the center of your base, then place other buildings around it to serve as decoys. The more decoy buildings that enemy troops have to destroy before reaching your true Keep, the better.